Who is Sam Flach from Give a Boy a Gun and what is their importance?

Sam Flach is a member of the Middletown football players. He believes that everyone is looking for someone to blame for the shootings, so they blame the athletes and the popular kids. Sam is Brendan and Gary's main target at the school dance. The kick him in the head, they and attempt to make him roll over, so they can shoot him in the knees.